1 // SPDX-License-Identifier: GPL-2.0
2 /****************************************************************************
3  *
4  * Driver for the IFX 6x60 spi modem.
5  *
6  * Copyright (C) 2008 Option International
7  * Copyright (C) 2008 Filip Aben <f.aben@option.com>
8  *		      Denis Joseph Barrow <d.barow@option.com>
9  *		      Jan Dumon <j.dumon@option.com>
10  *
11  * Copyright (C) 2009, 2010 Intel Corp
12  * Russ Gorby <russ.gorby@intel.com>
13  *
14  * Driver modified by Intel from Option gtm501l_spi.c
15  *
16  * Notes
17  * o	The driver currently assumes a single device only. If you need to
18  *	change this then look for saved_ifx_dev and add a device lookup
19  * o	The driver is intended to be big-endian safe but has never been
20  *	tested that way (no suitable hardware). There are a couple of FIXME
21  *	notes by areas that may need addressing
22  * o	Some of the GPIO naming/setup assumptions may need revisiting if
23  *	you need to use this driver for another platform.
24  *
25  *****************************************************************************/
26 #include <linux/dma-mapping.h>
27 #include <linux/module.h>
28 #include <linux/termios.h>
29 #include <linux/tty.h>
30 #include <linux/device.h>
31 #include <linux/spi/spi.h>
32 #include <linux/kfifo.h>
33 #include <linux/tty_flip.h>
34 #include <linux/timer.h>
35 #include <linux/serial.h>
36 #include <linux/interrupt.h>
37 #include <linux/irq.h>
38 #include <linux/rfkill.h>
39 #include <linux/fs.h>
40 #include <linux/ip.h>
41 #include <linux/dmapool.h>
42 #include <linux/gpio.h>
43 #include <linux/sched.h>
44 #include <linux/time.h>
45 #include <linux/wait.h>
46 #include <linux/pm.h>
47 #include <linux/pm_runtime.h>
48 #include <linux/spi/ifx_modem.h>
49 #include <linux/delay.h>
50 #include <linux/reboot.h>
51 
52 #include "ifx6x60.h"
53 
54 #define IFX_SPI_MORE_MASK		0x10
55 #define IFX_SPI_MORE_BIT		4	/* bit position in u8 */
56 #define IFX_SPI_CTS_BIT			6	/* bit position in u8 */
57 #define IFX_SPI_MODE			SPI_MODE_1
58 #define IFX_SPI_TTY_ID			0
59 #define IFX_SPI_TIMEOUT_SEC		2
60 #define IFX_SPI_HEADER_0		(-1)
61 #define IFX_SPI_HEADER_F		(-2)
62 
63 #define PO_POST_DELAY		200
64 #define IFX_MDM_RST_PMU	4
65 
66 /* forward reference */
67 static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev);
68 static int ifx_modem_reboot_callback(struct notifier_block *nfb,
69 				unsigned long event, void *data);
70 static int ifx_modem_power_off(struct ifx_spi_device *ifx_dev);
71 
72 /* local variables */
73 static int spi_bpw = 16;		/* 8, 16 or 32 bit word length */
74 static struct tty_driver *tty_drv;
75 static struct ifx_spi_device *saved_ifx_dev;
76 static struct lock_class_key ifx_spi_key;
77 
78 static struct notifier_block ifx_modem_reboot_notifier_block = {
79 	.notifier_call = ifx_modem_reboot_callback,
80 };
81 
ifx_modem_power_off(struct ifx_spi_device * ifx_dev)82 static int ifx_modem_power_off(struct ifx_spi_device *ifx_dev)
83 {
84 	gpio_set_value(IFX_MDM_RST_PMU, 1);
85 	msleep(PO_POST_DELAY);
86 
87 	return 0;
88 }
89 
ifx_modem_reboot_callback(struct notifier_block * nfb,unsigned long event,void * data)90 static int ifx_modem_reboot_callback(struct notifier_block *nfb,
91 				 unsigned long event, void *data)
92 {
93 	if (saved_ifx_dev)
94 		ifx_modem_power_off(saved_ifx_dev);
95 	else
96 		pr_warn("no ifx modem active;\n");
97 
98 	return NOTIFY_OK;
99 }
100 
101 /* GPIO/GPE settings */
102 
103 /**
104  *	mrdy_set_high		-	set MRDY GPIO
105  *	@ifx: device we are controlling
106  *
107  */
mrdy_set_high(struct ifx_spi_device * ifx)108 static inline void mrdy_set_high(struct ifx_spi_device *ifx)
109 {
110 	gpio_set_value(ifx->gpio.mrdy, 1);
111 }
112 
113 /**
114  *	mrdy_set_low		-	clear MRDY GPIO
115  *	@ifx: device we are controlling
116  *
117  */
mrdy_set_low(struct ifx_spi_device * ifx)118 static inline void mrdy_set_low(struct ifx_spi_device *ifx)
119 {
120 	gpio_set_value(ifx->gpio.mrdy, 0);
121 }
122 
123 /**
124  *	ifx_spi_power_state_set
125  *	@ifx_dev: our SPI device
126  *	@val: bits to set
127  *
128  *	Set bit in power status and signal power system if status becomes non-0
129  */
130 static void
ifx_spi_power_state_set(struct ifx_spi_device * ifx_dev,unsigned char val)131 ifx_spi_power_state_set(struct ifx_spi_device *ifx_dev, unsigned char val)
132 {
133 	unsigned long flags;
134 
135 	spin_lock_irqsave(&ifx_dev->power_lock, flags);
136 
137 	/*
138 	 * if power status is already non-0, just update, else
139 	 * tell power system
140 	 */
141 	if (!ifx_dev->power_status)
142 		pm_runtime_get(&ifx_dev->spi_dev->dev);
143 	ifx_dev->power_status |= val;
144 
145 	spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
146 }
147 
148 /**
149  *	ifx_spi_power_state_clear	-	clear power bit
150  *	@ifx_dev: our SPI device
151  *	@val: bits to clear
152  *
153  *	clear bit in power status and signal power system if status becomes 0
154  */
155 static void
ifx_spi_power_state_clear(struct ifx_spi_device * ifx_dev,unsigned char val)156 ifx_spi_power_state_clear(struct ifx_spi_device *ifx_dev, unsigned char val)
157 {
158 	unsigned long flags;
159 
160 	spin_lock_irqsave(&ifx_dev->power_lock, flags);
161 
162 	if (ifx_dev->power_status) {
163 		ifx_dev->power_status &= ~val;
164 		if (!ifx_dev->power_status)
165 			pm_runtime_put(&ifx_dev->spi_dev->dev);
166 	}
167 
168 	spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
169 }
170 
171 /**
172  *	swap_buf_8
173  *	@buf: our buffer
174  *	@len : number of bytes (not words) in the buffer
175  *	@end: end of buffer
176  *
177  *	Swap the contents of a buffer into big endian format
178  */
swap_buf_8(unsigned char * buf,int len,void * end)179 static inline void swap_buf_8(unsigned char *buf, int len, void *end)
180 {
181 	/* don't swap buffer if SPI word width is 8 bits */
182 	return;
183 }
184 
185 /**
186  *	swap_buf_16
187  *	@buf: our buffer
188  *	@len : number of bytes (not words) in the buffer
189  *	@end: end of buffer
190  *
191  *	Swap the contents of a buffer into big endian format
192  */
swap_buf_16(unsigned char * buf,int len,void * end)193 static inline void swap_buf_16(unsigned char *buf, int len, void *end)
194 {
195 	int n;
196 
197 	u16 *buf_16 = (u16 *)buf;
198 	len = ((len + 1) >> 1);
199 	if ((void *)&buf_16[len] > end) {
200 		pr_err("swap_buf_16: swap exceeds boundary (%p > %p)!",
201 		       &buf_16[len], end);
202 		return;
203 	}
204 	for (n = 0; n < len; n++) {
205 		*buf_16 = cpu_to_be16(*buf_16);
206 		buf_16++;
207 	}
208 }
209 
210 /**
211  *	swap_buf_32
212  *	@buf: our buffer
213  *	@len : number of bytes (not words) in the buffer
214  *	@end: end of buffer
215  *
216  *	Swap the contents of a buffer into big endian format
217  */
swap_buf_32(unsigned char * buf,int len,void * end)218 static inline void swap_buf_32(unsigned char *buf, int len, void *end)
219 {
220 	int n;
221 
222 	u32 *buf_32 = (u32 *)buf;
223 	len = (len + 3) >> 2;
224 
225 	if ((void *)&buf_32[len] > end) {
226 		pr_err("swap_buf_32: swap exceeds boundary (%p > %p)!\n",
227 		       &buf_32[len], end);
228 		return;
229 	}
230 	for (n = 0; n < len; n++) {
231 		*buf_32 = cpu_to_be32(*buf_32);
232 		buf_32++;
233 	}
234 }
235 
236 /**
237  *	mrdy_assert		-	assert MRDY line
238  *	@ifx_dev: our SPI device
239  *
240  *	Assert mrdy and set timer to wait for SRDY interrupt, if SRDY is low
241  *	now.
242  *
243  *	FIXME: Can SRDY even go high as we are running this code ?
244  */
mrdy_assert(struct ifx_spi_device * ifx_dev)245 static void mrdy_assert(struct ifx_spi_device *ifx_dev)
246 {
247 	int val = gpio_get_value(ifx_dev->gpio.srdy);
248 	if (!val) {
249 		if (!test_and_set_bit(IFX_SPI_STATE_TIMER_PENDING,
250 				      &ifx_dev->flags)) {
251 			mod_timer(&ifx_dev->spi_timer,jiffies + IFX_SPI_TIMEOUT_SEC*HZ);
252 
253 		}
254 	}
255 	ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_DATA_PENDING);
256 	mrdy_set_high(ifx_dev);
257 }
258 
259 /**
260  *	ifx_spi_timeout		-	SPI timeout
261  *	@arg: our SPI device
262  *
263  *	The SPI has timed out: hang up the tty. Users will then see a hangup
264  *	and error events.
265  */
ifx_spi_timeout(struct timer_list * t)266 static void ifx_spi_timeout(struct timer_list *t)
267 {
268 	struct ifx_spi_device *ifx_dev = from_timer(ifx_dev, t, spi_timer);
269 
270 	dev_warn(&ifx_dev->spi_dev->dev, "*** SPI Timeout ***");
271 	tty_port_tty_hangup(&ifx_dev->tty_port, false);
272 	mrdy_set_low(ifx_dev);
273 	clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
274 }
275 
276 /* char/tty operations */
277 
278 /**
279  *	ifx_spi_tiocmget	-	get modem lines
280  *	@tty: our tty device
281  *	@filp: file handle issuing the request
282  *
283  *	Map the signal state into Linux modem flags and report the value
284  *	in Linux terms
285  */
ifx_spi_tiocmget(struct tty_struct * tty)286 static int ifx_spi_tiocmget(struct tty_struct *tty)
287 {
288 	unsigned int value;
289 	struct ifx_spi_device *ifx_dev = tty->driver_data;
290 
291 	value =
292 	(test_bit(IFX_SPI_RTS, &ifx_dev->signal_state) ? TIOCM_RTS : 0) |
293 	(test_bit(IFX_SPI_DTR, &ifx_dev->signal_state) ? TIOCM_DTR : 0) |
294 	(test_bit(IFX_SPI_CTS, &ifx_dev->signal_state) ? TIOCM_CTS : 0) |
295 	(test_bit(IFX_SPI_DSR, &ifx_dev->signal_state) ? TIOCM_DSR : 0) |
296 	(test_bit(IFX_SPI_DCD, &ifx_dev->signal_state) ? TIOCM_CAR : 0) |
297 	(test_bit(IFX_SPI_RI, &ifx_dev->signal_state) ? TIOCM_RNG : 0);
298 	return value;
299 }
300 
301 /**
302  *	ifx_spi_tiocmset	-	set modem bits
303  *	@tty: the tty structure
304  *	@set: bits to set
305  *	@clear: bits to clear
306  *
307  *	The IFX6x60 only supports DTR and RTS. Set them accordingly
308  *	and flag that an update to the modem is needed.
309  *
310  *	FIXME: do we need to kick the tranfers when we do this ?
311  */
ifx_spi_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)312 static int ifx_spi_tiocmset(struct tty_struct *tty,
313 			    unsigned int set, unsigned int clear)
314 {
315 	struct ifx_spi_device *ifx_dev = tty->driver_data;
316 
317 	if (set & TIOCM_RTS)
318 		set_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
319 	if (set & TIOCM_DTR)
320 		set_bit(IFX_SPI_DTR, &ifx_dev->signal_state);
321 	if (clear & TIOCM_RTS)
322 		clear_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
323 	if (clear & TIOCM_DTR)
324 		clear_bit(IFX_SPI_DTR, &ifx_dev->signal_state);
325 
326 	set_bit(IFX_SPI_UPDATE, &ifx_dev->signal_state);
327 	return 0;
328 }
329 
330 /**
331  *	ifx_spi_open	-	called on tty open
332  *	@tty: our tty device
333  *	@filp: file handle being associated with the tty
334  *
335  *	Open the tty interface. We let the tty_port layer do all the work
336  *	for us.
337  *
338  *	FIXME: Remove single device assumption and saved_ifx_dev
339  */
ifx_spi_open(struct tty_struct * tty,struct file * filp)340 static int ifx_spi_open(struct tty_struct *tty, struct file *filp)
341 {
342 	return tty_port_open(&saved_ifx_dev->tty_port, tty, filp);
343 }
344 
345 /**
346  *	ifx_spi_close	-	called when our tty closes
347  *	@tty: the tty being closed
348  *	@filp: the file handle being closed
349  *
350  *	Perform the close of the tty. We use the tty_port layer to do all
351  *	our hard work.
352  */
ifx_spi_close(struct tty_struct * tty,struct file * filp)353 static void ifx_spi_close(struct tty_struct *tty, struct file *filp)
354 {
355 	struct ifx_spi_device *ifx_dev = tty->driver_data;
356 	tty_port_close(&ifx_dev->tty_port, tty, filp);
357 	/* FIXME: should we do an ifx_spi_reset here ? */
358 }
359 
360 /**
361  *	ifx_decode_spi_header	-	decode received header
362  *	@buffer: the received data
363  *	@length: decoded length
364  *	@more: decoded more flag
365  *	@received_cts: status of cts we received
366  *
367  *	Note how received_cts is handled -- if header is all F it is left
368  *	the same as it was, if header is all 0 it is set to 0 otherwise it is
369  *	taken from the incoming header.
370  *
371  *	FIXME: endianness
372  */
ifx_spi_decode_spi_header(unsigned char * buffer,int * length,unsigned char * more,unsigned char * received_cts)373 static int ifx_spi_decode_spi_header(unsigned char *buffer, int *length,
374 			unsigned char *more, unsigned char *received_cts)
375 {
376 	u16 h1;
377 	u16 h2;
378 	u16 *in_buffer = (u16 *)buffer;
379 
380 	h1 = *in_buffer;
381 	h2 = *(in_buffer+1);
382 
383 	if (h1 == 0 && h2 == 0) {
384 		*received_cts = 0;
385 		*more = 0;
386 		return IFX_SPI_HEADER_0;
387 	} else if (h1 == 0xffff && h2 == 0xffff) {
388 		*more = 0;
389 		/* spi_slave_cts remains as it was */
390 		return IFX_SPI_HEADER_F;
391 	}
392 
393 	*length = h1 & 0xfff;	/* upper bits of byte are flags */
394 	*more = (buffer[1] >> IFX_SPI_MORE_BIT) & 1;
395 	*received_cts = (buffer[3] >> IFX_SPI_CTS_BIT) & 1;
396 	return 0;
397 }
398 
399 /**
400  *	ifx_setup_spi_header	-	set header fields
401  *	@txbuffer: pointer to start of SPI buffer
402  *	@tx_count: bytes
403  *	@more: indicate if more to follow
404  *
405  *	Format up an SPI header for a transfer
406  *
407  *	FIXME: endianness?
408  */
ifx_spi_setup_spi_header(unsigned char * txbuffer,int tx_count,unsigned char more)409 static void ifx_spi_setup_spi_header(unsigned char *txbuffer, int tx_count,
410 					unsigned char more)
411 {
412 	*(u16 *)(txbuffer) = tx_count;
413 	*(u16 *)(txbuffer+2) = IFX_SPI_PAYLOAD_SIZE;
414 	txbuffer[1] |= (more << IFX_SPI_MORE_BIT) & IFX_SPI_MORE_MASK;
415 }
416 
417 /**
418  *	ifx_spi_prepare_tx_buffer	-	prepare transmit frame
419  *	@ifx_dev: our SPI device
420  *
421  *	The transmit buffr needs a header and various other bits of
422  *	information followed by as much data as we can pull from the FIFO
423  *	and transfer. This function formats up a suitable buffer in the
424  *	ifx_dev->tx_buffer
425  *
426  *	FIXME: performance - should we wake the tty when the queue is half
427  *			     empty ?
428  */
ifx_spi_prepare_tx_buffer(struct ifx_spi_device * ifx_dev)429 static int ifx_spi_prepare_tx_buffer(struct ifx_spi_device *ifx_dev)
430 {
431 	int temp_count;
432 	int queue_length;
433 	int tx_count;
434 	unsigned char *tx_buffer;
435 
436 	tx_buffer = ifx_dev->tx_buffer;
437 
438 	/* make room for required SPI header */
439 	tx_buffer += IFX_SPI_HEADER_OVERHEAD;
440 	tx_count = IFX_SPI_HEADER_OVERHEAD;
441 
442 	/* clear to signal no more data if this turns out to be the
443 	 * last buffer sent in a sequence */
444 	ifx_dev->spi_more = 0;
445 
446 	/* if modem cts is set, just send empty buffer */
447 	if (!ifx_dev->spi_slave_cts) {
448 		/* see if there's tx data */
449 		queue_length = kfifo_len(&ifx_dev->tx_fifo);
450 		if (queue_length != 0) {
451 			/* data to mux -- see if there's room for it */
452 			temp_count = min(queue_length, IFX_SPI_PAYLOAD_SIZE);
453 			temp_count = kfifo_out_locked(&ifx_dev->tx_fifo,
454 					tx_buffer, temp_count,
455 					&ifx_dev->fifo_lock);
456 
457 			/* update buffer pointer and data count in message */
458 			tx_buffer += temp_count;
459 			tx_count += temp_count;
460 			if (temp_count == queue_length)
461 				/* poke port to get more data */
462 				tty_port_tty_wakeup(&ifx_dev->tty_port);
463 			else /* more data in port, use next SPI message */
464 				ifx_dev->spi_more = 1;
465 		}
466 	}
467 	/* have data and info for header -- set up SPI header in buffer */
468 	/* spi header needs payload size, not entire buffer size */
469 	ifx_spi_setup_spi_header(ifx_dev->tx_buffer,
470 					tx_count-IFX_SPI_HEADER_OVERHEAD,
471 					ifx_dev->spi_more);
472 	/* swap actual data in the buffer */
473 	ifx_dev->swap_buf((ifx_dev->tx_buffer), tx_count,
474 		&ifx_dev->tx_buffer[IFX_SPI_TRANSFER_SIZE]);
475 	return tx_count;
476 }
477 
478 /**
479  *	ifx_spi_write		-	line discipline write
480  *	@tty: our tty device
481  *	@buf: pointer to buffer to write (kernel space)
482  *	@count: size of buffer
483  *
484  *	Write the characters we have been given into the FIFO. If the device
485  *	is not active then activate it, when the SRDY line is asserted back
486  *	this will commence I/O
487  */
ifx_spi_write(struct tty_struct * tty,const unsigned char * buf,int count)488 static int ifx_spi_write(struct tty_struct *tty, const unsigned char *buf,
489 			 int count)
490 {
491 	struct ifx_spi_device *ifx_dev = tty->driver_data;
492 	unsigned char *tmp_buf = (unsigned char *)buf;
493 	unsigned long flags;
494 	bool is_fifo_empty;
495 	int tx_count;
496 
497 	spin_lock_irqsave(&ifx_dev->fifo_lock, flags);
498 	is_fifo_empty = kfifo_is_empty(&ifx_dev->tx_fifo);
499 	tx_count = kfifo_in(&ifx_dev->tx_fifo, tmp_buf, count);
500 	spin_unlock_irqrestore(&ifx_dev->fifo_lock, flags);
501 	if (is_fifo_empty)
502 		mrdy_assert(ifx_dev);
503 
504 	return tx_count;
505 }
506 
507 /**
508  *	ifx_spi_chars_in_buffer	-	line discipline helper
509  *	@tty: our tty device
510  *
511  *	Report how much data we can accept before we drop bytes. As we use
512  *	a simple FIFO this is nice and easy.
513  */
ifx_spi_write_room(struct tty_struct * tty)514 static int ifx_spi_write_room(struct tty_struct *tty)
515 {
516 	struct ifx_spi_device *ifx_dev = tty->driver_data;
517 	return IFX_SPI_FIFO_SIZE - kfifo_len(&ifx_dev->tx_fifo);
518 }
519 
520 /**
521  *	ifx_spi_chars_in_buffer	-	line discipline helper
522  *	@tty: our tty device
523  *
524  *	Report how many characters we have buffered. In our case this is the
525  *	number of bytes sitting in our transmit FIFO.
526  */
ifx_spi_chars_in_buffer(struct tty_struct * tty)527 static int ifx_spi_chars_in_buffer(struct tty_struct *tty)
528 {
529 	struct ifx_spi_device *ifx_dev = tty->driver_data;
530 	return kfifo_len(&ifx_dev->tx_fifo);
531 }
532 
533 /**
534  *	ifx_port_hangup
535  *	@port: our tty port
536  *
537  *	tty port hang up. Called when tty_hangup processing is invoked either
538  *	by loss of carrier, or by software (eg vhangup). Serialized against
539  *	activate/shutdown by the tty layer.
540  */
ifx_spi_hangup(struct tty_struct * tty)541 static void ifx_spi_hangup(struct tty_struct *tty)
542 {
543 	struct ifx_spi_device *ifx_dev = tty->driver_data;
544 	tty_port_hangup(&ifx_dev->tty_port);
545 }
546 
547 /**
548  *	ifx_port_activate
549  *	@port: our tty port
550  *
551  *	tty port activate method - called for first open. Serialized
552  *	with hangup and shutdown by the tty layer.
553  */
ifx_port_activate(struct tty_port * port,struct tty_struct * tty)554 static int ifx_port_activate(struct tty_port *port, struct tty_struct *tty)
555 {
556 	struct ifx_spi_device *ifx_dev =
557 		container_of(port, struct ifx_spi_device, tty_port);
558 
559 	/* clear any old data; can't do this in 'close' */
560 	kfifo_reset(&ifx_dev->tx_fifo);
561 
562 	/* clear any flag which may be set in port shutdown procedure */
563 	clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags);
564 	clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags);
565 
566 	/* put port data into this tty */
567 	tty->driver_data = ifx_dev;
568 
569 	/* allows flip string push from int context */
570 	port->low_latency = 1;
571 
572 	/* set flag to allows data transfer */
573 	set_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags);
574 
575 	return 0;
576 }
577 
578 /**
579  *	ifx_port_shutdown
580  *	@port: our tty port
581  *
582  *	tty port shutdown method - called for last port close. Serialized
583  *	with hangup and activate by the tty layer.
584  */
ifx_port_shutdown(struct tty_port * port)585 static void ifx_port_shutdown(struct tty_port *port)
586 {
587 	struct ifx_spi_device *ifx_dev =
588 		container_of(port, struct ifx_spi_device, tty_port);
589 
590 	clear_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags);
591 	mrdy_set_low(ifx_dev);
592 	del_timer(&ifx_dev->spi_timer);
593 	clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
594 	tasklet_kill(&ifx_dev->io_work_tasklet);
595 }
596 
597 static const struct tty_port_operations ifx_tty_port_ops = {
598 	.activate = ifx_port_activate,
599 	.shutdown = ifx_port_shutdown,
600 };
601 
602 static const struct tty_operations ifx_spi_serial_ops = {
603 	.open = ifx_spi_open,
604 	.close = ifx_spi_close,
605 	.write = ifx_spi_write,
606 	.hangup = ifx_spi_hangup,
607 	.write_room = ifx_spi_write_room,
608 	.chars_in_buffer = ifx_spi_chars_in_buffer,
609 	.tiocmget = ifx_spi_tiocmget,
610 	.tiocmset = ifx_spi_tiocmset,
611 };
612 
613 /**
614  *	ifx_spi_insert_fip_string	-	queue received data
615  *	@ifx_ser: our SPI device
616  *	@chars: buffer we have received
617  *	@size: number of chars reeived
618  *
619  *	Queue bytes to the tty assuming the tty side is currently open. If
620  *	not the discard the data.
621  */
ifx_spi_insert_flip_string(struct ifx_spi_device * ifx_dev,unsigned char * chars,size_t size)622 static void ifx_spi_insert_flip_string(struct ifx_spi_device *ifx_dev,
623 				    unsigned char *chars, size_t size)
624 {
625 	tty_insert_flip_string(&ifx_dev->tty_port, chars, size);
626 	tty_flip_buffer_push(&ifx_dev->tty_port);
627 }
628 
629 /**
630  *	ifx_spi_complete	-	SPI transfer completed
631  *	@ctx: our SPI device
632  *
633  *	An SPI transfer has completed. Process any received data and kick off
634  *	any further transmits we can commence.
635  */
ifx_spi_complete(void * ctx)636 static void ifx_spi_complete(void *ctx)
637 {
638 	struct ifx_spi_device *ifx_dev = ctx;
639 	int length;
640 	int actual_length;
641 	unsigned char more = 0;
642 	unsigned char cts;
643 	int local_write_pending = 0;
644 	int queue_length;
645 	int srdy;
646 	int decode_result;
647 
648 	mrdy_set_low(ifx_dev);
649 
650 	if (!ifx_dev->spi_msg.status) {
651 		/* check header validity, get comm flags */
652 		ifx_dev->swap_buf(ifx_dev->rx_buffer, IFX_SPI_HEADER_OVERHEAD,
653 			&ifx_dev->rx_buffer[IFX_SPI_HEADER_OVERHEAD]);
654 		decode_result = ifx_spi_decode_spi_header(ifx_dev->rx_buffer,
655 				&length, &more, &cts);
656 		if (decode_result == IFX_SPI_HEADER_0) {
657 			dev_dbg(&ifx_dev->spi_dev->dev,
658 				"ignore input: invalid header 0");
659 			ifx_dev->spi_slave_cts = 0;
660 			goto complete_exit;
661 		} else if (decode_result == IFX_SPI_HEADER_F) {
662 			dev_dbg(&ifx_dev->spi_dev->dev,
663 				"ignore input: invalid header F");
664 			goto complete_exit;
665 		}
666 
667 		ifx_dev->spi_slave_cts = cts;
668 
669 		actual_length = min((unsigned int)length,
670 					ifx_dev->spi_msg.actual_length);
671 		ifx_dev->swap_buf(
672 			(ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD),
673 			 actual_length,
674 			 &ifx_dev->rx_buffer[IFX_SPI_TRANSFER_SIZE]);
675 		ifx_spi_insert_flip_string(
676 			ifx_dev,
677 			ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD,
678 			(size_t)actual_length);
679 	} else {
680 		more = 0;
681 		dev_dbg(&ifx_dev->spi_dev->dev, "SPI transfer error %d",
682 		       ifx_dev->spi_msg.status);
683 	}
684 
685 complete_exit:
686 	if (ifx_dev->write_pending) {
687 		ifx_dev->write_pending = 0;
688 		local_write_pending = 1;
689 	}
690 
691 	clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &(ifx_dev->flags));
692 
693 	queue_length = kfifo_len(&ifx_dev->tx_fifo);
694 	srdy = gpio_get_value(ifx_dev->gpio.srdy);
695 	if (!srdy)
696 		ifx_spi_power_state_clear(ifx_dev, IFX_SPI_POWER_SRDY);
697 
698 	/* schedule output if there is more to do */
699 	if (test_and_clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags))
700 		tasklet_schedule(&ifx_dev->io_work_tasklet);
701 	else {
702 		if (more || ifx_dev->spi_more || queue_length > 0 ||
703 			local_write_pending) {
704 			if (ifx_dev->spi_slave_cts) {
705 				if (more)
706 					mrdy_assert(ifx_dev);
707 			} else
708 				mrdy_assert(ifx_dev);
709 		} else {
710 			/*
711 			 * poke line discipline driver if any for more data
712 			 * may or may not get more data to write
713 			 * for now, say not busy
714 			 */
715 			ifx_spi_power_state_clear(ifx_dev,
716 						  IFX_SPI_POWER_DATA_PENDING);
717 			tty_port_tty_wakeup(&ifx_dev->tty_port);
718 		}
719 	}
720 }
721 
722 /**
723  *	ifx_spio_io		-	I/O tasklet
724  *	@data: our SPI device
725  *
726  *	Queue data for transmission if possible and then kick off the
727  *	transfer.
728  */
ifx_spi_io(unsigned long data)729 static void ifx_spi_io(unsigned long data)
730 {
731 	int retval;
732 	struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *) data;
733 
734 	if (!test_and_set_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags) &&
735 		test_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags)) {
736 		if (ifx_dev->gpio.unack_srdy_int_nb > 0)
737 			ifx_dev->gpio.unack_srdy_int_nb--;
738 
739 		ifx_spi_prepare_tx_buffer(ifx_dev);
740 
741 		spi_message_init(&ifx_dev->spi_msg);
742 		INIT_LIST_HEAD(&ifx_dev->spi_msg.queue);
743 
744 		ifx_dev->spi_msg.context = ifx_dev;
745 		ifx_dev->spi_msg.complete = ifx_spi_complete;
746 
747 		/* set up our spi transfer */
748 		/* note len is BYTES, not transfers */
749 		ifx_dev->spi_xfer.len = IFX_SPI_TRANSFER_SIZE;
750 		ifx_dev->spi_xfer.cs_change = 0;
751 		ifx_dev->spi_xfer.speed_hz = ifx_dev->spi_dev->max_speed_hz;
752 		/* ifx_dev->spi_xfer.speed_hz = 390625; */
753 		ifx_dev->spi_xfer.bits_per_word =
754 			ifx_dev->spi_dev->bits_per_word;
755 
756 		ifx_dev->spi_xfer.tx_buf = ifx_dev->tx_buffer;
757 		ifx_dev->spi_xfer.rx_buf = ifx_dev->rx_buffer;
758 
759 		/*
760 		 * setup dma pointers
761 		 */
762 		if (ifx_dev->use_dma) {
763 			ifx_dev->spi_msg.is_dma_mapped = 1;
764 			ifx_dev->tx_dma = ifx_dev->tx_bus;
765 			ifx_dev->rx_dma = ifx_dev->rx_bus;
766 			ifx_dev->spi_xfer.tx_dma = ifx_dev->tx_dma;
767 			ifx_dev->spi_xfer.rx_dma = ifx_dev->rx_dma;
768 		} else {
769 			ifx_dev->spi_msg.is_dma_mapped = 0;
770 			ifx_dev->tx_dma = (dma_addr_t)0;
771 			ifx_dev->rx_dma = (dma_addr_t)0;
772 			ifx_dev->spi_xfer.tx_dma = (dma_addr_t)0;
773 			ifx_dev->spi_xfer.rx_dma = (dma_addr_t)0;
774 		}
775 
776 		spi_message_add_tail(&ifx_dev->spi_xfer, &ifx_dev->spi_msg);
777 
778 		/* Assert MRDY. This may have already been done by the write
779 		 * routine.
780 		 */
781 		mrdy_assert(ifx_dev);
782 
783 		retval = spi_async(ifx_dev->spi_dev, &ifx_dev->spi_msg);
784 		if (retval) {
785 			clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS,
786 				  &ifx_dev->flags);
787 			tasklet_schedule(&ifx_dev->io_work_tasklet);
788 			return;
789 		}
790 	} else
791 		ifx_dev->write_pending = 1;
792 }
793 
794 /**
795  *	ifx_spi_free_port	-	free up the tty side
796  *	@ifx_dev: IFX device going away
797  *
798  *	Unregister and free up a port when the device goes away
799  */
ifx_spi_free_port(struct ifx_spi_device * ifx_dev)800 static void ifx_spi_free_port(struct ifx_spi_device *ifx_dev)
801 {
802 	if (ifx_dev->tty_dev)
803 		tty_unregister_device(tty_drv, ifx_dev->minor);
804 	tty_port_destroy(&ifx_dev->tty_port);
805 	kfifo_free(&ifx_dev->tx_fifo);
806 }
807 
808 /**
809  *	ifx_spi_create_port	-	create a new port
810  *	@ifx_dev: our spi device
811  *
812  *	Allocate and initialise the tty port that goes with this interface
813  *	and add it to the tty layer so that it can be opened.
814  */
ifx_spi_create_port(struct ifx_spi_device * ifx_dev)815 static int ifx_spi_create_port(struct ifx_spi_device *ifx_dev)
816 {
817 	int ret = 0;
818 	struct tty_port *pport = &ifx_dev->tty_port;
819 
820 	spin_lock_init(&ifx_dev->fifo_lock);
821 	lockdep_set_class_and_subclass(&ifx_dev->fifo_lock,
822 		&ifx_spi_key, 0);
823 
824 	if (kfifo_alloc(&ifx_dev->tx_fifo, IFX_SPI_FIFO_SIZE, GFP_KERNEL)) {
825 		ret = -ENOMEM;
826 		goto error_ret;
827 	}
828 
829 	tty_port_init(pport);
830 	pport->ops = &ifx_tty_port_ops;
831 	ifx_dev->minor = IFX_SPI_TTY_ID;
832 	ifx_dev->tty_dev = tty_port_register_device(pport, tty_drv,
833 			ifx_dev->minor, &ifx_dev->spi_dev->dev);
834 	if (IS_ERR(ifx_dev->tty_dev)) {
835 		dev_dbg(&ifx_dev->spi_dev->dev,
836 			"%s: registering tty device failed", __func__);
837 		ret = PTR_ERR(ifx_dev->tty_dev);
838 		goto error_port;
839 	}
840 	return 0;
841 
842 error_port:
843 	tty_port_destroy(pport);
844 error_ret:
845 	ifx_spi_free_port(ifx_dev);
846 	return ret;
847 }
848 
849 /**
850  *	ifx_spi_handle_srdy		-	handle SRDY
851  *	@ifx_dev: device asserting SRDY
852  *
853  *	Check our device state and see what we need to kick off when SRDY
854  *	is asserted. This usually means killing the timer and firing off the
855  *	I/O processing.
856  */
ifx_spi_handle_srdy(struct ifx_spi_device * ifx_dev)857 static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev)
858 {
859 	if (test_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags)) {
860 		del_timer(&ifx_dev->spi_timer);
861 		clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
862 	}
863 
864 	ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_SRDY);
865 
866 	if (!test_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags))
867 		tasklet_schedule(&ifx_dev->io_work_tasklet);
868 	else
869 		set_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags);
870 }
871 
872 /**
873  *	ifx_spi_srdy_interrupt	-	SRDY asserted
874  *	@irq: our IRQ number
875  *	@dev: our ifx device
876  *
877  *	The modem asserted SRDY. Handle the srdy event
878  */
ifx_spi_srdy_interrupt(int irq,void * dev)879 static irqreturn_t ifx_spi_srdy_interrupt(int irq, void *dev)
880 {
881 	struct ifx_spi_device *ifx_dev = dev;
882 	ifx_dev->gpio.unack_srdy_int_nb++;
883 	ifx_spi_handle_srdy(ifx_dev);
884 	return IRQ_HANDLED;
885 }
886 
887 /**
888  *	ifx_spi_reset_interrupt	-	Modem has changed reset state
889  *	@irq: interrupt number
890  *	@dev: our device pointer
891  *
892  *	The modem has either entered or left reset state. Check the GPIO
893  *	line to see which.
894  *
895  *	FIXME: review locking on MR_INPROGRESS versus
896  *	parallel unsolicited reset/solicited reset
897  */
ifx_spi_reset_interrupt(int irq,void * dev)898 static irqreturn_t ifx_spi_reset_interrupt(int irq, void *dev)
899 {
900 	struct ifx_spi_device *ifx_dev = dev;
901 	int val = gpio_get_value(ifx_dev->gpio.reset_out);
902 	int solreset = test_bit(MR_START, &ifx_dev->mdm_reset_state);
903 
904 	if (val == 0) {
905 		/* entered reset */
906 		set_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
907 		if (!solreset) {
908 			/* unsolicited reset  */
909 			tty_port_tty_hangup(&ifx_dev->tty_port, false);
910 		}
911 	} else {
912 		/* exited reset */
913 		clear_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
914 		if (solreset) {
915 			set_bit(MR_COMPLETE, &ifx_dev->mdm_reset_state);
916 			wake_up(&ifx_dev->mdm_reset_wait);
917 		}
918 	}
919 	return IRQ_HANDLED;
920 }
921 
922 /**
923  *	ifx_spi_free_device - free device
924  *	@ifx_dev: device to free
925  *
926  *	Free the IFX device
927  */
ifx_spi_free_device(struct ifx_spi_device * ifx_dev)928 static void ifx_spi_free_device(struct ifx_spi_device *ifx_dev)
929 {
930 	ifx_spi_free_port(ifx_dev);
931 	dma_free_coherent(&ifx_dev->spi_dev->dev,
932 				IFX_SPI_TRANSFER_SIZE,
933 				ifx_dev->tx_buffer,
934 				ifx_dev->tx_bus);
935 	dma_free_coherent(&ifx_dev->spi_dev->dev,
936 				IFX_SPI_TRANSFER_SIZE,
937 				ifx_dev->rx_buffer,
938 				ifx_dev->rx_bus);
939 }
940 
941 /**
942  *	ifx_spi_reset	-	reset modem
943  *	@ifx_dev: modem to reset
944  *
945  *	Perform a reset on the modem
946  */
ifx_spi_reset(struct ifx_spi_device * ifx_dev)947 static int ifx_spi_reset(struct ifx_spi_device *ifx_dev)
948 {
949 	int ret;
950 	/*
951 	 * set up modem power, reset
952 	 *
953 	 * delays are required on some platforms for the modem
954 	 * to reset properly
955 	 */
956 	set_bit(MR_START, &ifx_dev->mdm_reset_state);
957 	gpio_set_value(ifx_dev->gpio.po, 0);
958 	gpio_set_value(ifx_dev->gpio.reset, 0);
959 	msleep(25);
960 	gpio_set_value(ifx_dev->gpio.reset, 1);
961 	msleep(1);
962 	gpio_set_value(ifx_dev->gpio.po, 1);
963 	msleep(1);
964 	gpio_set_value(ifx_dev->gpio.po, 0);
965 	ret = wait_event_timeout(ifx_dev->mdm_reset_wait,
966 				 test_bit(MR_COMPLETE,
967 					  &ifx_dev->mdm_reset_state),
968 				 IFX_RESET_TIMEOUT);
969 	if (!ret)
970 		dev_warn(&ifx_dev->spi_dev->dev, "Modem reset timeout: (state:%lx)",
971 			 ifx_dev->mdm_reset_state);
972 
973 	ifx_dev->mdm_reset_state = 0;
974 	return ret;
975 }
976 
977 /**
978  *	ifx_spi_spi_probe	-	probe callback
979  *	@spi: our possible matching SPI device
980  *
981  *	Probe for a 6x60 modem on SPI bus. Perform any needed device and
982  *	GPIO setup.
983  *
984  *	FIXME:
985  *	-	Support for multiple devices
986  *	-	Split out MID specific GPIO handling eventually
987  */
988 
ifx_spi_spi_probe(struct spi_device * spi)989 static int ifx_spi_spi_probe(struct spi_device *spi)
990 {
991 	int ret;
992 	int srdy;
993 	struct ifx_modem_platform_data *pl_data;
994 	struct ifx_spi_device *ifx_dev;
995 
996 	if (saved_ifx_dev) {
997 		dev_dbg(&spi->dev, "ignoring subsequent detection");
998 		return -ENODEV;
999 	}
1000 
1001 	pl_data = dev_get_platdata(&spi->dev);
1002 	if (!pl_data) {
1003 		dev_err(&spi->dev, "missing platform data!");
1004 		return -ENODEV;
1005 	}
1006 
1007 	/* initialize structure to hold our device variables */
1008 	ifx_dev = kzalloc(sizeof(struct ifx_spi_device), GFP_KERNEL);
1009 	if (!ifx_dev) {
1010 		dev_err(&spi->dev, "spi device allocation failed");
1011 		return -ENOMEM;
1012 	}
1013 	saved_ifx_dev = ifx_dev;
1014 	ifx_dev->spi_dev = spi;
1015 	clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags);
1016 	spin_lock_init(&ifx_dev->write_lock);
1017 	spin_lock_init(&ifx_dev->power_lock);
1018 	ifx_dev->power_status = 0;
1019 	timer_setup(&ifx_dev->spi_timer, ifx_spi_timeout, 0);
1020 	ifx_dev->modem = pl_data->modem_type;
1021 	ifx_dev->use_dma = pl_data->use_dma;
1022 	ifx_dev->max_hz = pl_data->max_hz;
1023 	/* initialize spi mode, etc */
1024 	spi->max_speed_hz = ifx_dev->max_hz;
1025 	spi->mode = IFX_SPI_MODE | (SPI_LOOP & spi->mode);
1026 	spi->bits_per_word = spi_bpw;
1027 	ret = spi_setup(spi);
1028 	if (ret) {
1029 		dev_err(&spi->dev, "SPI setup wasn't successful %d", ret);
1030 		kfree(ifx_dev);
1031 		return -ENODEV;
1032 	}
1033 
1034 	/* init swap_buf function according to word width configuration */
1035 	if (spi->bits_per_word == 32)
1036 		ifx_dev->swap_buf = swap_buf_32;
1037 	else if (spi->bits_per_word == 16)
1038 		ifx_dev->swap_buf = swap_buf_16;
1039 	else
1040 		ifx_dev->swap_buf = swap_buf_8;
1041 
1042 	/* ensure SPI protocol flags are initialized to enable transfer */
1043 	ifx_dev->spi_more = 0;
1044 	ifx_dev->spi_slave_cts = 0;
1045 
1046 	/*initialize transfer and dma buffers */
1047 	ifx_dev->tx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent,
1048 				IFX_SPI_TRANSFER_SIZE,
1049 				&ifx_dev->tx_bus,
1050 				GFP_KERNEL);
1051 	if (!ifx_dev->tx_buffer) {
1052 		dev_err(&spi->dev, "DMA-TX buffer allocation failed");
1053 		ret = -ENOMEM;
1054 		goto error_ret;
1055 	}
1056 	ifx_dev->rx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent,
1057 				IFX_SPI_TRANSFER_SIZE,
1058 				&ifx_dev->rx_bus,
1059 				GFP_KERNEL);
1060 	if (!ifx_dev->rx_buffer) {
1061 		dev_err(&spi->dev, "DMA-RX buffer allocation failed");
1062 		ret = -ENOMEM;
1063 		goto error_ret;
1064 	}
1065 
1066 	/* initialize waitq for modem reset */
1067 	init_waitqueue_head(&ifx_dev->mdm_reset_wait);
1068 
1069 	spi_set_drvdata(spi, ifx_dev);
1070 	tasklet_init(&ifx_dev->io_work_tasklet, ifx_spi_io,
1071 						(unsigned long)ifx_dev);
1072 
1073 	set_bit(IFX_SPI_STATE_PRESENT, &ifx_dev->flags);
1074 
1075 	/* create our tty port */
1076 	ret = ifx_spi_create_port(ifx_dev);
1077 	if (ret != 0) {
1078 		dev_err(&spi->dev, "create default tty port failed");
1079 		goto error_ret;
1080 	}
1081 
1082 	ifx_dev->gpio.reset = pl_data->rst_pmu;
1083 	ifx_dev->gpio.po = pl_data->pwr_on;
1084 	ifx_dev->gpio.mrdy = pl_data->mrdy;
1085 	ifx_dev->gpio.srdy = pl_data->srdy;
1086 	ifx_dev->gpio.reset_out = pl_data->rst_out;
1087 
1088 	dev_info(&spi->dev, "gpios %d, %d, %d, %d, %d",
1089 		 ifx_dev->gpio.reset, ifx_dev->gpio.po, ifx_dev->gpio.mrdy,
1090 		 ifx_dev->gpio.srdy, ifx_dev->gpio.reset_out);
1091 
1092 	/* Configure gpios */
1093 	ret = gpio_request(ifx_dev->gpio.reset, "ifxModem");
1094 	if (ret < 0) {
1095 		dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET)",
1096 			ifx_dev->gpio.reset);
1097 		goto error_ret;
1098 	}
1099 	ret += gpio_direction_output(ifx_dev->gpio.reset, 0);
1100 	ret += gpio_export(ifx_dev->gpio.reset, 1);
1101 	if (ret) {
1102 		dev_err(&spi->dev, "Unable to configure GPIO%d (RESET)",
1103 			ifx_dev->gpio.reset);
1104 		ret = -EBUSY;
1105 		goto error_ret2;
1106 	}
1107 
1108 	ret = gpio_request(ifx_dev->gpio.po, "ifxModem");
1109 	ret += gpio_direction_output(ifx_dev->gpio.po, 0);
1110 	ret += gpio_export(ifx_dev->gpio.po, 1);
1111 	if (ret) {
1112 		dev_err(&spi->dev, "Unable to configure GPIO%d (ON)",
1113 			ifx_dev->gpio.po);
1114 		ret = -EBUSY;
1115 		goto error_ret3;
1116 	}
1117 
1118 	ret = gpio_request(ifx_dev->gpio.mrdy, "ifxModem");
1119 	if (ret < 0) {
1120 		dev_err(&spi->dev, "Unable to allocate GPIO%d (MRDY)",
1121 			ifx_dev->gpio.mrdy);
1122 		goto error_ret3;
1123 	}
1124 	ret += gpio_export(ifx_dev->gpio.mrdy, 1);
1125 	ret += gpio_direction_output(ifx_dev->gpio.mrdy, 0);
1126 	if (ret) {
1127 		dev_err(&spi->dev, "Unable to configure GPIO%d (MRDY)",
1128 			ifx_dev->gpio.mrdy);
1129 		ret = -EBUSY;
1130 		goto error_ret4;
1131 	}
1132 
1133 	ret = gpio_request(ifx_dev->gpio.srdy, "ifxModem");
1134 	if (ret < 0) {
1135 		dev_err(&spi->dev, "Unable to allocate GPIO%d (SRDY)",
1136 			ifx_dev->gpio.srdy);
1137 		ret = -EBUSY;
1138 		goto error_ret4;
1139 	}
1140 	ret += gpio_export(ifx_dev->gpio.srdy, 1);
1141 	ret += gpio_direction_input(ifx_dev->gpio.srdy);
1142 	if (ret) {
1143 		dev_err(&spi->dev, "Unable to configure GPIO%d (SRDY)",
1144 			ifx_dev->gpio.srdy);
1145 		ret = -EBUSY;
1146 		goto error_ret5;
1147 	}
1148 
1149 	ret = gpio_request(ifx_dev->gpio.reset_out, "ifxModem");
1150 	if (ret < 0) {
1151 		dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET_OUT)",
1152 			ifx_dev->gpio.reset_out);
1153 		goto error_ret5;
1154 	}
1155 	ret += gpio_export(ifx_dev->gpio.reset_out, 1);
1156 	ret += gpio_direction_input(ifx_dev->gpio.reset_out);
1157 	if (ret) {
1158 		dev_err(&spi->dev, "Unable to configure GPIO%d (RESET_OUT)",
1159 			ifx_dev->gpio.reset_out);
1160 		ret = -EBUSY;
1161 		goto error_ret6;
1162 	}
1163 
1164 	ret = request_irq(gpio_to_irq(ifx_dev->gpio.reset_out),
1165 			  ifx_spi_reset_interrupt,
1166 			  IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING, DRVNAME,
1167 			  ifx_dev);
1168 	if (ret) {
1169 		dev_err(&spi->dev, "Unable to get irq %x\n",
1170 			gpio_to_irq(ifx_dev->gpio.reset_out));
1171 		goto error_ret6;
1172 	}
1173 
1174 	ret = ifx_spi_reset(ifx_dev);
1175 
1176 	ret = request_irq(gpio_to_irq(ifx_dev->gpio.srdy),
1177 			  ifx_spi_srdy_interrupt, IRQF_TRIGGER_RISING, DRVNAME,
1178 			  ifx_dev);
1179 	if (ret) {
1180 		dev_err(&spi->dev, "Unable to get irq %x",
1181 			gpio_to_irq(ifx_dev->gpio.srdy));
1182 		goto error_ret7;
1183 	}
1184 
1185 	/* set pm runtime power state and register with power system */
1186 	pm_runtime_set_active(&spi->dev);
1187 	pm_runtime_enable(&spi->dev);
1188 
1189 	/* handle case that modem is already signaling SRDY */
1190 	/* no outgoing tty open at this point, this just satisfies the
1191 	 * modem's read and should reset communication properly
1192 	 */
1193 	srdy = gpio_get_value(ifx_dev->gpio.srdy);
1194 
1195 	if (srdy) {
1196 		mrdy_assert(ifx_dev);
1197 		ifx_spi_handle_srdy(ifx_dev);
1198 	} else
1199 		mrdy_set_low(ifx_dev);
1200 	return 0;
1201 
1202 error_ret7:
1203 	free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), ifx_dev);
1204 error_ret6:
1205 	gpio_free(ifx_dev->gpio.srdy);
1206 error_ret5:
1207 	gpio_free(ifx_dev->gpio.mrdy);
1208 error_ret4:
1209 	gpio_free(ifx_dev->gpio.reset);
1210 error_ret3:
1211 	gpio_free(ifx_dev->gpio.po);
1212 error_ret2:
1213 	gpio_free(ifx_dev->gpio.reset_out);
1214 error_ret:
1215 	ifx_spi_free_device(ifx_dev);
1216 	saved_ifx_dev = NULL;
1217 	return ret;
1218 }
1219 
1220 /**
1221  *	ifx_spi_spi_remove	-	SPI device was removed
1222  *	@spi: SPI device
1223  *
1224  *	FIXME: We should be shutting the device down here not in
1225  *	the module unload path.
1226  */
1227 
ifx_spi_spi_remove(struct spi_device * spi)1228 static int ifx_spi_spi_remove(struct spi_device *spi)
1229 {
1230 	struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
1231 	/* stop activity */
1232 	tasklet_kill(&ifx_dev->io_work_tasklet);
1233 	/* free irq */
1234 	free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), ifx_dev);
1235 	free_irq(gpio_to_irq(ifx_dev->gpio.srdy), ifx_dev);
1236 
1237 	gpio_free(ifx_dev->gpio.srdy);
1238 	gpio_free(ifx_dev->gpio.mrdy);
1239 	gpio_free(ifx_dev->gpio.reset);
1240 	gpio_free(ifx_dev->gpio.po);
1241 	gpio_free(ifx_dev->gpio.reset_out);
1242 
1243 	/* free allocations */
1244 	ifx_spi_free_device(ifx_dev);
1245 
1246 	saved_ifx_dev = NULL;
1247 	return 0;
1248 }
1249 
1250 /**
1251  *	ifx_spi_spi_shutdown	-	called on SPI shutdown
1252  *	@spi: SPI device
1253  *
1254  *	No action needs to be taken here
1255  */
1256 
ifx_spi_spi_shutdown(struct spi_device * spi)1257 static void ifx_spi_spi_shutdown(struct spi_device *spi)
1258 {
1259 	struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
1260 
1261 	ifx_modem_power_off(ifx_dev);
1262 }
1263 
1264 /*
1265  * various suspends and resumes have nothing to do
1266  * no hardware to save state for
1267  */
1268 
1269 /**
1270  *	ifx_spi_pm_suspend	-	suspend modem on system suspend
1271  *	@dev: device being suspended
1272  *
1273  *	Suspend the modem. No action needed on Intel MID platforms, may
1274  *	need extending for other systems.
1275  */
ifx_spi_pm_suspend(struct device * dev)1276 static int ifx_spi_pm_suspend(struct device *dev)
1277 {
1278 	return 0;
1279 }
1280 
1281 /**
1282  *	ifx_spi_pm_resume	-	resume modem on system resume
1283  *	@dev: device being suspended
1284  *
1285  *	Allow the modem to resume. No action needed.
1286  *
1287  *	FIXME: do we need to reset anything here ?
1288  */
ifx_spi_pm_resume(struct device * dev)1289 static int ifx_spi_pm_resume(struct device *dev)
1290 {
1291 	return 0;
1292 }
1293 
1294 /**
1295  *	ifx_spi_pm_runtime_resume	-	suspend modem
1296  *	@dev: device being suspended
1297  *
1298  *	Allow the modem to resume. No action needed.
1299  */
ifx_spi_pm_runtime_resume(struct device * dev)1300 static int ifx_spi_pm_runtime_resume(struct device *dev)
1301 {
1302 	return 0;
1303 }
1304 
1305 /**
1306  *	ifx_spi_pm_runtime_suspend	-	suspend modem
1307  *	@dev: device being suspended
1308  *
1309  *	Allow the modem to suspend and thus suspend to continue up the
1310  *	device tree.
1311  */
ifx_spi_pm_runtime_suspend(struct device * dev)1312 static int ifx_spi_pm_runtime_suspend(struct device *dev)
1313 {
1314 	return 0;
1315 }
1316 
1317 /**
1318  *	ifx_spi_pm_runtime_idle		-	check if modem idle
1319  *	@dev: our device
1320  *
1321  *	Check conditions and queue runtime suspend if idle.
1322  */
ifx_spi_pm_runtime_idle(struct device * dev)1323 static int ifx_spi_pm_runtime_idle(struct device *dev)
1324 {
1325 	struct spi_device *spi = to_spi_device(dev);
1326 	struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
1327 
1328 	if (!ifx_dev->power_status)
1329 		pm_runtime_suspend(dev);
1330 
1331 	return 0;
1332 }
1333 
1334 static const struct dev_pm_ops ifx_spi_pm = {
1335 	.resume = ifx_spi_pm_resume,
1336 	.suspend = ifx_spi_pm_suspend,
1337 	.runtime_resume = ifx_spi_pm_runtime_resume,
1338 	.runtime_suspend = ifx_spi_pm_runtime_suspend,
1339 	.runtime_idle = ifx_spi_pm_runtime_idle
1340 };
1341 
1342 static const struct spi_device_id ifx_id_table[] = {
1343 	{"ifx6160", 0},
1344 	{"ifx6260", 0},
1345 	{ }
1346 };
1347 MODULE_DEVICE_TABLE(spi, ifx_id_table);
1348 
1349 /* spi operations */
1350 static struct spi_driver ifx_spi_driver = {
1351 	.driver = {
1352 		.name = DRVNAME,
1353 		.pm = &ifx_spi_pm,
1354 	},
1355 	.probe = ifx_spi_spi_probe,
1356 	.shutdown = ifx_spi_spi_shutdown,
1357 	.remove = ifx_spi_spi_remove,
1358 	.id_table = ifx_id_table
1359 };
1360 
1361 /**
1362  *	ifx_spi_exit	-	module exit
1363  *
1364  *	Unload the module.
1365  */
1366 
ifx_spi_exit(void)1367 static void __exit ifx_spi_exit(void)
1368 {
1369 	/* unregister */
1370 	spi_unregister_driver(&ifx_spi_driver);
1371 	tty_unregister_driver(tty_drv);
1372 	put_tty_driver(tty_drv);
1373 	unregister_reboot_notifier(&ifx_modem_reboot_notifier_block);
1374 }
1375 
1376 /**
1377  *	ifx_spi_init		-	module entry point
1378  *
1379  *	Initialise the SPI and tty interfaces for the IFX SPI driver
1380  *	We need to initialize upper-edge spi driver after the tty
1381  *	driver because otherwise the spi probe will race
1382  */
1383 
ifx_spi_init(void)1384 static int __init ifx_spi_init(void)
1385 {
1386 	int result;
1387 
1388 	tty_drv = alloc_tty_driver(1);
1389 	if (!tty_drv) {
1390 		pr_err("%s: alloc_tty_driver failed", DRVNAME);
1391 		return -ENOMEM;
1392 	}
1393 
1394 	tty_drv->driver_name = DRVNAME;
1395 	tty_drv->name = TTYNAME;
1396 	tty_drv->minor_start = IFX_SPI_TTY_ID;
1397 	tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
1398 	tty_drv->subtype = SERIAL_TYPE_NORMAL;
1399 	tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1400 	tty_drv->init_termios = tty_std_termios;
1401 
1402 	tty_set_operations(tty_drv, &ifx_spi_serial_ops);
1403 
1404 	result = tty_register_driver(tty_drv);
1405 	if (result) {
1406 		pr_err("%s: tty_register_driver failed(%d)",
1407 			DRVNAME, result);
1408 		goto err_free_tty;
1409 	}
1410 
1411 	result = spi_register_driver(&ifx_spi_driver);
1412 	if (result) {
1413 		pr_err("%s: spi_register_driver failed(%d)",
1414 			DRVNAME, result);
1415 		goto err_unreg_tty;
1416 	}
1417 
1418 	result = register_reboot_notifier(&ifx_modem_reboot_notifier_block);
1419 	if (result) {
1420 		pr_err("%s: register ifx modem reboot notifier failed(%d)",
1421 			DRVNAME, result);
1422 		goto err_unreg_spi;
1423 	}
1424 
1425 	return 0;
1426 err_unreg_spi:
1427 	spi_unregister_driver(&ifx_spi_driver);
1428 err_unreg_tty:
1429 	tty_unregister_driver(tty_drv);
1430 err_free_tty:
1431 	put_tty_driver(tty_drv);
1432 
1433 	return result;
1434 }
1435 
1436 module_init(ifx_spi_init);
1437 module_exit(ifx_spi_exit);
1438 
1439 MODULE_AUTHOR("Intel");
1440 MODULE_DESCRIPTION("IFX6x60 spi driver");
1441 MODULE_LICENSE("GPL");
1442 MODULE_INFO(Version, "0.1-IFX6x60");
1443